fix(player): the stacked layout's minimum width no longer clips the wide one

The 36rem floor guards the stacked layout's width/height feedback loop; the
wide side-panel card has no such loop, and on a short wide window the floor
made the video taller than the card, cutting off YouTube's control bar. The
floor now applies to the stacked layout only; e2e covers a 1400x380 window.

frontend/e2e/player.spec.ts

@@ -29,7 +29,8 @@ test.describe("player modal", () => {
 
 // The video's size, in the windows the owner meets: layout bugs no DOM test can see. Each viewport
 // is a real one — 1920×911 is a 1080p screen at 100% (the side-panel layout), 1097×520 the same
-// screen at 175% or a small laptop at 100% (the stacked layout, on a short window).
+// screen at 175% or a small laptop at 100% (the stacked layout, on a short window), 1400×380 a wide
+// window made short by docked devtools (the side-panel layout, whose card does not scroll).
 test.describe("player modal sizing", () => {
   test.beforeEach(async ({ page }) => {
     await page.route(/youtube\.com/, (route) => route.abort());
@@ -41,6 +42,7 @@ test.describe("player modal sizing", () => {
   for (const [w, h] of [
     [1920, 911],
     [1097, 520],
+    [1400, 380],
   ] as const) {
     test(`the video keeps a real size at ${w}×${h}, and maximised fills the window`, async ({
       page,
@@ -54,6 +56,16 @@ test.describe("player modal sizing", () => {
       const stage = await box(page, ".player-stage");
       expect(stage.width).toBeGreaterThanOrEqual(Math.min(w * 0.5, 560));
       expect(stage.height).toBeGreaterThan(stage.width * 0.5);
+      // …and all of it is in sight: its bottom edge is the YouTube control bar, and the side-panel
+      // card clips what overflows it (it does not scroll), the stacked card scrolls to it.
+      const overflow = await page
+        .locator(".player-stage")
+        .first()
+        .evaluate((el) => {
+          const card = el.parentElement!;
+          return el.getBoundingClientRect().bottom - card.getBoundingClientRect().bottom;
+        });
+      expect(overflow).toBeLessThanOrEqual(0.5);
 
       // Maximise (F): the stage is fixed to the viewport. In the side-panel layout its `self-start`
       // once aligned the fixed box too, and it shrank to its content's height — 0 px, a thin line.

frontend/src/components/PlayerModal.dom.test.tsx

@@ -512,7 +512,7 @@ describe("PlayerModal — the side panel on a wide window", () => {
     expect(screen.queryByRole("button", { name: "player.description" })).toBeNull();
     // The row's width: the video at the window's height, plus the panel and the side strips.
     expect(card.parentElement!.style.maxWidth).toBe(
-      "calc(max(36rem, (100dvh - 3rem - 0px) * 16 / 9) + 20rem + 7rem)",
+      "calc((100dvh - 3rem - 0px) * 16 / 9 + 20rem + 7rem)",
     );
   });
 

frontend/src/components/PlayerModal.tsx

@@ -104,7 +104,7 @@ function canScrollBy(el: HTMLElement | null, dir: -1 | 1): boolean {
 // a rem width, so it grows with the text size; the video takes what is left.
 const WIDE_PLAYER_PX = 1280;
 const SIDE_PANEL = "20rem";
-// The narrowest the video gets to make room for the chrome under it (see the card's maxWidth).
+// The narrowest the stacked video gets to make room for the chrome under it (see the card's maxWidth).
 const MIN_VIDEO = "36rem";
 
 // The meta line's items each lead with a "·" that parts them from what stands before: the channel name
@@ -614,7 +614,7 @@ export default function PlayerModal({
   };
 
   // The card's width budget (its maxWidth, below): the video's, and the side strips' gutters.
-  const videoWidth = `max(${MIN_VIDEO}, (100dvh - 3rem - ${below}px) * 16 / 9)`;
+  const fitWidth = `(100dvh - 3rem - ${below}px) * 16 / 9`;
   const gutters = hasQueue ? " + 7rem" : "";
 
   // Portaled to <body>, like every other full-screen overlay here. A fixed, full-viewport modal
@@ -641,14 +641,16 @@ export default function PlayerModal({
         className={`relative flex w-full max-h-full ${hasQueue ? "sm:px-14" : ""}`}
         // The design width (63rem with the side strips, else 56rem), narrowed so the 16:9 video plus the
         // chrome under it fits the window's height less the backdrop's padding (`p-6` = 3rem).
-        // Wide: no design cap — the video is as wide as the window's height allows, plus the side panel.
-        // Never narrower than MIN_VIDEO: the chrome under the video grows as the card narrows (its text
-        // wraps), so on a short window fitting it was a loop that ran the card down to 2 px (a laptop
-        // at 100%, a 1080p screen at 175%). Past the floor the card scrolls instead.
+        // Wide: no design cap — the video is as wide as the window's height allows, plus the side panel,
+        // whose content sits beside the video (`below` is ~0), so the fit is exact and the card, which
+        // does not scroll there, always holds the whole video.
+        // Stacked: never narrower than MIN_VIDEO. The chrome under the video grows as the card narrows
+        // (its text wraps), so on a short window fitting it was a loop that ran the card down to 2 px
+        // (a laptop at 100%, a 1080p screen at 175%). Past the floor the stacked card scrolls instead.
         style={{
           maxWidth: wide
-            ? `calc(${videoWidth} + ${SIDE_PANEL}${gutters})`
-            : `min(${hasQueue ? "63rem" : "56rem"}, calc(${videoWidth}${gutters}))`,
+            ? `calc(${fitWidth} + ${SIDE_PANEL}${gutters})`
+            : `min(${hasQueue ? "63rem" : "56rem"}, calc(max(${MIN_VIDEO}, ${fitWidth})${gutters}))`,
         }}
       >
         {hasQueue && (